Selig, the longtime owner of the Milwaukee Brewers, was elected as permanent MLB commissioner by his fellow owners in July 1998—he had been acting commissioner since September 1992. He turned 79 in July. Selig’s legacy is a complicated one, and will be greatly debated between now and his actual retirement date.

On one hand, the sport is largely a financial success; revenues have reached record levels during his time as baseball’s leader. Because of that success, there have been no major labor issues since the ugly strike that cancelled the 1994 World Series. And whether it’s directly his responsibility or not, under his watch MLB has been at the forefront of the digital sports revolution with MLB.com.

On the other hand, much of the blame the steroid era has been cast at his feet—for a long time, baseball turned a blind eye to the problem. There is the fiasco with the A’s in Oakland; the team wants to move to a new stadium San Jose, and MLB has drug its feet on this issue for years. Then there was the All-Star Game debacle in 2002, when the game ended in a tie and MLB’s knee-jerk reaction was to make the outcome of that game determine home-field advantage in the World Series.

"I look forward to continuing its extraordinary growth and addressing several significant issues during the remainder of my term," he said.

Selig said he will soon announce a transition plan that will include a reorganization of central baseball management.

He said he will leave on Jan. 24, 2015, which would mark the second-longest term for a baseball commissioner behind Kenesaw Mountain Landis, who served from November 1920 to November 1944.

A quick look at some of baseball’s more controversial on-field innovations under Selig:

1994: REALIGNMENT

The move from the four-division format, which had been in place since 1969, to the six-division format happened prior to the 1994 season. Coincidentally, it coincided with the cancellation of the World Series for the first time since 1904.

1994: THE WILD CARD

Logistically, it went into effect simultaneously with realignment. However, the first wild-card teams (Yankees and Rockies) weren’t crowned until 1995, thanks to the absence of a 1994 postseason. By adding a wild card in each league, another round of playoffs (and an additional opportunity for revenue) was created. The Marlins (1997, 2003), Angels (2002), Red Sox (2004) and Cardinals (2011) have won the World Series as wild cards.

1997: INTERLEAGUE PLAY

On June 12, 1997, the Rangers hosted the Giants in the first American League vs. National League matchup outside of the All-Star Game and World Series.

1998: EXPANSION

The Marlins and Rockies entered the league in 1993, but that plan was in place prior to Selig’s tenure. In 1998, the majors welcomed the Devil Rays and Diamondbacks. As a result, the Brewers, still owned by Selig’s family, moved from the A.L. to the N.L.

2003: LINKING THE WORLD SERIES AND ALL-STAR GAME

Seeking to elevate the midsummer classic from exhibition status (and attempting to erase the embarrassing memory of the tie in the 2002 All-Star Game), in 2003, Selig implemented a plan to raise the stakes. Instead of rotating home-field advantage in the World Series between the leagues, it was awarded to the league that had won the All-Star Game that season.

2012: A SECOND WILD-CARD TEAM

More teams involved in a postseason chase means more excitement (and increased revenues), right? The Cardinals claimed the extra wild-card spot in the National League and beat the Braves in the one-game wild-card round, then knocked off the Nationals and took a 3-1 lead in the NLCS before the Giants came roaring back. In the AL, the Orioles and Rangers finished deadlocked with 93 wins, and the Orioles won the wild-card game.